Can axillary node dissection be safely omitted in the elderly? A retrospective study on axillary management of early breast cancer in older women.

INTRODUCTION: Sentinel lymph node biopsy (SLNB) is a minimally invasive technique to stage the axillary lymph node status. The burden of nodal metastasis is of great concern, as the clinical relevance and therapeutic implications of pN1mi and pN0(i+) in the sentinel lymph node (SLN) remain a matter of debate.

MATERIALS AND METHODS: We examined the pathological features of 901 patients above the age of 65 presenting with clinical T1-T2 N0M0 breast tumours (<3 cm), detecting tumours related to llary non-sentinel node (NSN) metastases when the SLN was minimally involved.

RESULTS: A total of 270 patients underwent complete axillary lymph node dissection (cALND) after their SLNB specimen tested positive for macrometastasis, micrometastasis and isolated tumour cells (ITCs). Seventy-six patients were diagnosed with micrometastatic disease pN1mi (27.5%), whilst ITCs (pN0i+) were detected in seven patients (2.5%). NSNs were found to be involved in two patients (2.6%) with micrometastases at the SLN. No further metastatic disease was detected in NSNs when the SLN contained ITCs. At a median follow-up period of 5.8 years, no axillary recurrence was observed among pN1mi and pN0(i+) patients. Lobular histotype, multicentricity and lymphovascular invasion were found to be associated with NSN involvement.

DISCUSSION: The results from our case series are supported by IBCSG 23-01 level 1 evidence, which demonstrated a local recurrence rate of 1% in 'minimally involved not-surgical treated axilla'.

CONCLUSIONS: Based on current evidence, we spare well-informed and consenting patients from further axillary surgery when the SLN is minimally involved in early breast cancer within an agreed protocol, whilst scheduling adjuvant treatment based on the patients' primary tumour characteristics.